Date: 20/05/2010

3-channel HB LED driver by Semtech to enhance LCD display illumination

Semtech unveiled the SC446, a 3-channel high brightness LED (HB LED) driver with an integrated 2.5A boost power switch. It is said to have the capability of driving up to 36 HB LEDs at up to 100mA per channel. It operates across an input voltage range of 4.5V to 27V and has a high output range of up to 42V. It is used in applications where LED's reliability, shock resistance and mercury-free benefits dispatch CFL bulbs, these applications include indoor/outdoor displays for automotive, industrial, white goods, avionics, medical and gaming equipment.

SC446 provides good LCD illumination with up to 100mA per-channel and operate at low operating temperature and has long life at high ambient conditions. Its 1mm pin spacing minimizes the risk of pin-to-pin faults. The SC446 has an internal boost switch that is said to provide high efficiency (greater than 92%). It PWM dimming of Up to 50kHz reduces audio noise problems. The internal DC-DC current mode controller maintains the optimum LED output voltage. Parallel channels can be used for applications requiring low component stress and temperature rise and the channels can also be independently disabled. The controller switching frequency is maintained at 700kHz for low external L/C filter size and high operating efficiency. It provides a smooth transition from boost to bypass operating mode, when the input voltage is greater than the output voltage. Current sinks are rated up to 40V. It is compatible with the SEPIC converter topology, where the input voltage is greater than, or less than, the output voltage.

"The transition from CCFL to LED backlights gives LCD panel manufacturers and systems integrators a simple, cost-effective option for improving the temperature profile and shock ruggedness of their designs," said Steve Hawley, Semtech Product Marketing Manager for LED Lighting and Displays. "The SC446 offers a driver solution that matches the reliability of the high brightness LEDs themselves."

Package: 16-pin thermally enhanced TSSOP.

Price: Each US$1.65 in 2,500-piece lots

Availability: Now

For more information visit: www.semtech.com/info.